public class Example3_6 {
  public static void main(String args[]) {
    double sum = 0,item = 1;
    int i = 1,n = 20;
    while(i<=n) {
       sum = sum+item;
       i = i+1;
       item = item*(1.0/i);
    }
    System.out.println("sum="+sum);
  }
}
